The formulation of hydrocarbon and oxygen containing fuels and lubricants typically includes additives comprising a variety of chemicals to improve properties in application specific situations, particularly gasoline and diesel internal combustion engines. The more commonly used additives include oxidation inhibitors, rust inhibitors, metal passivators, antiwear agents, extreme pressure additives, pour point depressants, detergent-dispersants, lube viscosity index (VI) improvers, foam inhibitors and the like. The scope of the operating conditions to which internal combustion engines are subjected can readily result in lubricant degradation, leading to sludge buildup and excessive engine wear. The foregoing additives serve to control this problem in various ways. In the lubricant arts, this aspect is specifically described in Kirk-Othmer "Encyclopedia of Chemical Technology", 3rd edition, Vol. 14, pp 477-526, incorporated herein by reference.
It is known that alkenyl succinimides prepared from alkenyl succinic anhydrides and polyalkyleneamines are effective as additives to provide ashless dispersancy. These are typically prepared from materials such as polyisobutenyl succinic anhydride and tetraethylene penatamine. Examples of such succinimides are described in U.S. Pat. Nos. 3,024,237, 3,172,892, 3,202,678, 3,219,666 and 3,257,554. It is also known that further derivation of alkenyl succinimides can be accomplished to enhance the dispersant properties of these succinimides or to augment these properties with additional functions, such as improved antioxidant properties and the like.
In U.S. Pat. No. 3,573,205, Lowe suggests the reaction product of alkenyl succinimide and diisocyanate as a lubricant additive. Brown, in U.S. Pat. No. 3,844,965, discloses the reaction product of a hydrocarbyl sustituted cyclic imide lube oil ashless dispersant with an organic polyisocyanate and a polyoxyalkylene polyol as an antirust additive.
In U.S. Pat. No. 4,713,191 to Nalesnik it is disclosed that lubricant additives can be prepared from coupling alkenyl succinimides using hydroxycarboxylic acids and diisocyanates.
The U.S. Pat. No. 4,116,875 to Nmadi et al discloses lubricant additives comprising bis-alkenyl succinimides coupled by hetercyclic compounds. The heterocyclic compounds include triazenes. The triazene may be further reacted, in one embodiment, to produce a lactam amino group. Further, in U.S. Pat. No. 4,113,725, Nmadi et al provides structures for lubricant additives employing hetercyclic nitrogen compounds including triazenes, plus alkenyl succinimides.
In U.S. Pat. No. 4,464,276, Sung et al discloses benzotriazole complexes with polyoxyalkylene polyamines. The patent discloses the use of alkenly succinimide/polyamines with the products of the invention as lubricant additives.
Nebzydoski et al, in U.S. Pat. No. 4,283,296, discloses triazole based lubricating oil additives where the triazole moiety is incorporated into succinamic acid by C substitution on the triazole ring. The patentee employed, 3-amino-1, 2, 4-triazole as reactant with alkyl substituted succinic anhydride to produce and claim an amine salt as the reaction product.
Fused ring triazoles, such as benzotriazole, are known to exhibit metal passivating or anti-corrosive properties, particularly with copper based metals. They are, as well, potentially useful as antioxidants. Accordingly, the present invention is concerned with the incorporation of triazoles into molecular structures known to exhibit useful additive properties, such as alkenyl succinimides, to provide improved additives offering a multifunctional dimension as additives for fuels or lubricants. While the foregoing cited prior art describes triazole based lube additives and also the diisocyanate coupling of alkenyl succinimides, the prior art does not teach the method or compositions of the present invention wherein triazoles are coupled with alkenyl succinimides using diisocyanates.
It is an object of the present invention to provide novel, multifunctional fuel and lubricant additives incorporating triazole moieties and alkenyl succinimides.
It is another object of the instant invention to provide a method for producing the foregoing novel, multi-functional additives for mineral oil or synthetic lubricants.
Another object of the invention is to provide novel fuel and lubricant compositions incorporating the additives of the present invention.